The sale was going to net Yahoo around $7.1 billion. With that cash, the plan was, "to return substantially all of the after-tax cash proceeds to shareholders following the closing of the transaction."

It looks like Mayer didn't agree with that plan.

According to an SEC filing, Mayer is reviewing Yahoo's plans for the cash, and, "This review process may lead to a reevaluation of, or changes to, our current plans, including our restructuring plan, our share repurchase program, and our previously announced plans for returning to shareholders substantially all of the after tax cash proceeds of the initial share repurchase under the Share Repurchase and Preference Share Sale Agreement we entered into on May 20, 2012 with Alibaba Group Holding Limited."

It will be interesting to see how Dan Loeb, the activist hedge funder who got her the job, reacts to this news. Presumably, he'll be happy. It suggests Mayer is going to spend the money on something that can breath new life into the company. Spending it on share buybacks wasn't going to make Yahoo a stronger company.

The stock is falling 5% in after hours trading.

Here's the short, but powerful paragraph in the filing:

On July 17, 2012, Marissa Mayer became the Chief Executive Officer and a member of the Board of Directors of Yahoo! Inc. (the “Company”). As reported in our Form 10-Q for the quarter ended June 30, 2012 filed today with the Securities and Exchange Commission, Ms. Mayer is engaging in a review of the Company’s business strategy to enhance long term shareholder value. As part of that review, Ms. Mayer intends to review with the Board of Directors, among other things, the Company’s growth and acquisition strategy, the restructuring plan we began implementing in the second quarter of 2012, and the Company’s cash position and planned capital allocation strategy. This review process may lead to a reevaluation of, or changes to, our current plans, including our restructuring plan, our share repurchase program, and our previously announced plans for returning to shareholders substantially all of the after tax cash proceeds of the initial share repurchase under the Share Repurchase and Preference Share Sale Agreement we entered into on May 20, 2012 with Alibaba Group Holding Limited.